<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <script src="https://cdn.staticfile.org/react/16.4.0/umd/react.development.js"></script>
    <script src="https://cdn.staticfile.org/react-dom/16.4.0/umd/react-dom.development.js"></script>
    <!-- 生产环境中不建议使用 -->
    <script src="https://cdn.staticfile.org/babel-standalone/6.26.0/babel.min.js"></script>
    <script src="https://cdn.bootcss.com/fetch/3.0.0/fetch.min.js"></script>
    <title>React 表单</title>
</head>

<body>
    <div id="app">

    </div>
</body>
<script type="text/babel">
        class Guo extends React.Component{
            constructor() {
                super();
                this.state ={
                    arr:[]
                }
            }

            componentWillMount(){
                //挂载之前获取数据
                console.log('開始获取数据');
                this.ajaxToData()          
            }

            ajaxToData(){
               console.log(fetch);
               fetch('http://localhost:3001/get',{
                   method:'GET'
               }).then((res)=>{
                //    console.log(res)
                   res.json((res)=>{

                   }).then((res)=>{
                       console.log(res)
                       this.setState({
                           arr: res
                       })
                   })
               })
               
            }
            
            
            render(){
                let arrLi = [];
                this.state.arr.forEach((val,index)=>{
                    arrLi.push(<li key={index}>{val}</li>)
                });

                return (<div>
                            <div style={{display: this.state.arr.length > 0 ?'none':'block'}}>暂无数据...</div>
                            <ul>
                                {arrLi}
                            </ul>
                        </div>)
            }
        }
        ReactDOM.render(<Guo/>,app)
    </script>

</html>